1. Field of the Invention
The present invention relates to a kinematic arrangement for the micro-movements of objects also over large distances. In particular, the kinematic arrangement serves for imparting movement to and the manipulation of objects which are to be investigated microscopically.
2. Description of the Prior Art
Mechanically highly-precise operating sequences, in an increasing measure, are required in the modern micro-technology. The mechanical control elements which have been heretofore employed for this purpose to the greatest extent, and which are equipped with lever systems, gears and micrometer screws, in many instances cannot meet the necessary demands. In order to carry out micro-movements, electromagnetic or piezoelectric control elements are better suited for such purposes.
For instance, extremely precise micro-movements are necessary for the Scanning-Tunneling Microscope (STM), described in the article "Das Raster-Tunnelmicroscop", by G. Binnig and H. Rohrer, Helvetia Phys. Acta--55, 1982, page 726. The STM necessitates the highest degree of precision and stability for the movement of the object under investigation. Thus, for the scanning of the object, as well as for the manipulation of the object, a prerequisite is precision movements within the nanometer range in order to achieve the desired results. These movements must be carried out and controlled dependably, repeatedly and rapidly.
The currently known control elements for STM's utilize a combination of three piezoelectric control elements for the scanning operation (a tripod with one control element in each of the three coordinate directions x, y, z) and further control elements for the manipulation of the object which operate either piezoelectrically, electromagnetically or mechanically, G. Binnig and H. Rohrer, "Das Raster-Tunnelmikroskop", Spektrum der Wissenschaft, 1985, pages 62-68; J. Moreland, et al., "Electromagnetic Squeezer for Compressing Squeezable Electron Tunnel Junctions", Rev. Sci. Instrum., 55, 1984, page 399. The complex construction of these control elements is susceptible to disturbances; vibrations and temperature drifts are almost impossible to avoid. Moreover, critical is the necessity of a high voltage operation of these elements.
A two-directional piezoelectric driven fine adjusting device is disclosed in Ishikawa, U.S. Pat. No. 4,163,168, in which first and second counter piezo-electric members which are fixed to each other are expandable and contractable in directions differing from each other responsive to the selective application of electrical signals. Slide members are fixed to the piezoelectric members and some into sliding contact with a base and electrical attraction devices which are responsive to applied electrical signals for attracting and fasting the slide members to a movable plate. The device disclosed herein is cumbersome and does not afford the accuracy of movement contemplated by the inventive kinematic arrangement.